Abstract [en]

The aim of this Project is to study the influence of high return temperatures in district heating on the costs for heat and power production in a CHP plant.When the temperatures of the water coming back to the heating plant are so high, the overall performance of heat and power production is decreased and, consequently, also the production costs. Along the project, the influence of this temperature on the different parts of a CHP plant are analysed as well as the economical impact it has. At the same time, some general impacts on the entire network are mentioned.

A real network is used in this project, and it is the net of district heating in Gävle (Sweden), and the most of the study is focus in its bigger combined heat and power production plant (CHP), called Johannes.